In the TaNaKH it is very clear that the ritual of Circumcision (Heb: brit milah בְּרִית מִילָה ) was the SEAL of the covenant (Gen. 17:9-14) between God and community of believers (Abrahamic seeds: Heb: zera‘ זֶרַע ) we read in Genesis 17:10:
zoth beriti asher tishmeru beni uvenekhem uvein zar’a-kha acharei-kha himmol lakhem kal-zakar
This is My covenant, which ye shall keep, between Me and you, and your seed after you: every male among you shall be circumcised.
After that event God then mandated Abraham to perform the first ritual of Circumcision and subsequently to his seed (Heb: זֶרַע zera’ ) including Prophet Jesus and Muhammad (peace be upon them all).
The gospel of Luke 2:21 mentions Jesus’ circumcision and formal naming and from about the 6th century or so in the Western churches, 1 January was designated as the Feast of the Circumcision of Jesus (eight days after 25 Dec), and over the centuries Jesus’ foreskin (prepuce), which many churches claimed to possess, was worshiped as the “Holy Grail” of Christian relics.
Interestingly however the circumcision is the least celebrated event the Christendom, since the medieval period, the date of Feast of the Circumcision of Jesus was treated as another feast dedicated to devotion to Jesus’ mother, Mary. This is an absolute contrast to the muslim world where the circumcision (Arabic: Khitan ختان) is celebrated as an Islamic culture by Muslims. It is accepted as established practice by all Islamic schools of jurisprudence as obligatory on all male Muslims.
The abandon of the practice of circumcision in the christendom is evident when one looks at much of church history where it appears to ignore the topic and even more evident in church art. If one goes through the many paintings of the nude infant Jesus in the christian paintings, he appears uncircumcised (like the one below by Pietro Perugino’s Madonna and Child). This glaring and obvious falsification of biblical history and abandonment of Abrahamic covenant proves that Christianity has deviated from the straight path of God.